Firewalls - I Do Not Think It Means What You Think It Means!

It’s a great (frigid) day here in Orem, Utah! I have a long-time inspector friend, Ken Ives, from Sacramento, California, that has always given me a hard time when I referred to a water heater as a hot water heater. Kind of like fingernails scraping on a chalkboard, this has always been Ken’s pet peeve. For years I regularly made him squint when he read my messages referring to hot water heaters. and he pounced on me every time I did until I finally purged “hot water heater” from my vocabulary. Well I have a similar pet peeve, and it deals with home inspectors referring to the walls in residential garages as “Firewalls”.

Is the wall in a home’s garage really a firewall?

As home inspectors we need to write with exactness and be able to back up our terminology and references in our reports with official documentation, otherwise we put ourselves in a libelous situation. Typically the terms we use come from the national and local building codes and/or manufacturer installation specs. Many times we use local or regional terms that everybody in the local building industry understand, but are not found in the codes. We use these slang or local terms to help convey our thoughts to the layman. For example, the term “barge rafters” is a terms that has clear meaning to those in the greater Northwest, yet in another part of the country people say, “What is a barge rafter?”

Well “Firewall” is one of those words that everybody seems to know what you are talking about, but if you were called into court after the home burned down from a garage fire and you stated the “The garage firewall is in good condition,” then you would be in sad shape. You would not be in a defensible position and your lawyer would NOT be able to go to the building codes to help justify your written statements... Really? Is it that big of deal? Yep! When we are talking about residential construction, it is rare when the walls of a garage are actually firewalls. So it is my recommendation that the term be purged from everyday home inspector use in both our verbal and written communication, and replaced with terminology that is more exact.

Let me take you on a knowledge quest to find out the definition of “Firewall” and see what words/phrases we should be using in its place to improve our accuracy and precision in the reporting of our inspection findings. On our journey we will visit the International Residential Code (IRC), the International Building Code (IBC), NFPA 221 (National Fire Protection Association), the California Building Code (CBC), and even Wikipedia.

FIREWALL QUESTION

But first, let’s look at the great question and photo shared by Ken Ives.

“Maybe I was on Maui for too long (if that is even possible), but I saw this today and it looked odd. PVC exhaust piping thru the ceiling of a garage. Is this a fire wall compromise issue?” Ken Ives - Sacramento, CA - www.KenIves.com

The photo shows two plastic PVC furnace vent pipes that penetrate the drywall in a Sacramento, Ca. area garage. Many of the warmer climate California homes have their furnaces located inside the garage. One of these pipes brings fresh air to the high efficiency furnace and the other is the exhaust vent taking the exhaust to the exterior of the home. The questions Ken Ives is asking are:

1) Can meltable plastic piping be used out in the open of a garage to pass through the drywall?

2) Is the penetration acceptable, or does their need to be a metal collar or fire rated sealant around the pipe?

3) Is the drywall covering referred to as a fire wall? (Okay, Ken didn’t ask that, but he did refer to a fire wall and that ruffled the hair on the back of my neck)

The answers to Ken’s questions are complicated because Ken inspects in California, and California refused to adopt the the International Residential Code(IRC) as their guide. Instead, they use a similar version of codes called the California Building Code (CBC) that greatly resembles the IRC, but let’s face it, California has earthquakes so let’s allow them continue to create a more stringent building code to help save lives when the earth starts to shake.

ONLINE BUILDER’S DISCUSSION

I reviewed some online information where California builders discussed the topic of PVC pipes penetrating the garage walls and here is some of their dialogue...

2" ABS vent pipe in garage fire wall

We have a residential project that has a garage wall next to the addition. We have 5/8" gyp. board on that common wall. There is a washer and a dryer in the garage. The contractor has run a 2" ABS vent through the fire wall into the attic above the addition, and apparently there is an ABS drainage pipe going through the fire wall also. The inspector says this has to be metal.

Looking in the 2007 CBC (basically the same as the IBC), in Section 406.1.4, in part 2 it does say that "ducts penetrating the walls or ceilings separating the dwelling unit from the garage shall be constructed of a min. of 0.019-inch sheet metal" however the ABS is not a duct. If we do need to have metal on it could we wrap the section of the ABS with a sleeve of the sheet metal?

I was caught off guard with the response from Southern California that stated...

“Typically, the plumbers around here (SOCAL) transition from ABS to cast iron pipe/fire caulk at the garage penetrations.....”

I have never seen them do that here in Utah. The SOCAL responder was referring to black plastic ABS pipe being used as drain line for the plumbing system. This doesn’t directly apply for our furnace situation because cast iron has NEVER been used (to my knowledge) for vent piping in high efficiency furnace installations. But this is a case where the local AHJ (Authority Having Jurisdiction), the code enforcement official, raised the standard and is enforcing a more stringent requirement.

Here is another suggested option,

”Build a box around it, install 5/8" drywall, tape and mud?“

This is not a viable furnace vent pipe solution because the vent piping originates in the garage and you can’t box it in all the way to the furnace that is located in the garage.

And yet another solution...

“...put an intumescent fire collar on it and you're done, OR you can also just change out the penetrations to cast iron.”

The same building code forum gave lots of advice, with most of it varying due to the contributors being from different parts of the United States.

BUILDING CODE REFERENCES

So let’s get down to business. As a residential building inspector, when I need a definition or understanding, I go right to the source and refer what the International Residential Code (IRC) has to say. So let’s review the garage portion of the IRC as it refers to the walls and the penetrations through the walls. I will highlight red the important parts for this discussion...

SECTION R309GARAGES AND CARPORTSR309.1 Opening protection.Openings from a private garage directly into a room used for sleeping purposes shall not be permitted. Other openings between the garage and residence shall be equipped with solid wood doors not less than 13/8 inches (35 mm) in thickness, solid or honeycomb core steel doors not less than 13/8 inches (35 mm) thick, or 20-minute fire-rated doors.R309.1.1 Duct penetration.Ducts in the garage and ducts penetrating the walls or ceilings separating the dwelling from the garage shall be constructed of a minimum No. 26 gage (0.48 mm) sheet steel or other approved material and shall have no openings into the garage.R309.1.2 Other penetrations.Penetrations through the separation required in Section R309.2 shall be protected by filling the opening around the penetrating item with approved material to resist the free passage of flame and products of combustion.R309.2 Separation required.The garage shall be separated from the residence and its attic area by not less than ½-inch (12.7 mm) gypsum board applied to the garage side. Garages beneath habitable rooms shall be separated from all habitable rooms above by not less than 5/8-inch (15.9 mm) Type X gypsum board or equivalent. Where the separation is a floor-ceiling assembly, the structure supporting the separation shall also be protected by not less than 1/2-inch (12.7 mm) gypsum board or equivalent. Garages located less than 3 feet (914 mm) from a dwelling unit on the same lot shall be protected with not less than ½-inch (12.7 mm) gypsum board applied to the interior side of exterior walls that are within this area. Openings in these walls shall be regulated by Section R309.1. This provision does not apply to garage walls that are perpendicular to the adjacent dwelling unit wall.

We learn a lot about garages in this small section of the IRC, but Ken Ives’ answer is found in R309.1.2. Most people mistakenly refer to R309.1.1 and want to treat Ken’s situation as a duct penetration, but the intake and exhaust vent pipes are not ducts, and therefore they do not need to be boxed out. R309.1.2 is the appropriate application of the building codes.

Now I challenge you to go back to the IRC and find the term fire wall or firewall. Doing a search on the complete IRC text finds no results. Why? Because firewalls is a term used in the International Building Code (IBC) for commercial construction and not a residential building code term. (MORE ON THAT FARTHER DOWN THE PAGE).

Looking at the IRC garage section we find garage references to:

1) walls or ceilings separating the dwelling from the garage

2) Penetrations through the separation walls

3) Separation required

4) The garage shall be separated from the residence

5) Where the separation is a floor-ceiling assembly

There is also a section of the IRC talking about addition retrofits to existing structures...

AJ601.3 Separation walls.Where the work area is in an attached dwelling unit, walls separating dwelling units that are not continuous from the foundation to the underside of the roof sheathing shall be constructed to provide a continuous fire separation using construction materials consistent with the existing wall or complying with the requirements for new structures. Performance of work shall be required only on the side of the wall of the dwelling unit that is part of the work area.

FIRE WALL VERSES FIRE SEPARATION WALL

Does it really make any difference whether we use the term firewall or fire separation wall?

Since the IRC does not contain the term “Firewall” then we should consider not using it. Instead, we can safely use the terms, separation wall, fire separation wall, and non-continuous fire separation wall. For example, when we are in a condominium attic with a gypsum board type separation wall that has run from the foundation all the way to the roof between the units, then it is a continuous fire separation wall. But let’s be real clear, there is no mention of a “Firewall” or “Fire Wall” in the IRC. Why? Because this term is reserved for larger construction codes in the International Building Code (IBC) and the word firewall contains a much deeper meaning.

WHAT IS A FIREWALL?

First, I opened up the IBC to search for a definition for “Firewall” and found two applicable definitions in Section 702.1 for this discussion...

INTERNATIONAL BUILDING CODEFIRE BARRIER. A fire-resistance-rated wall assembly of materials designed to restrict the spread of fire in which continuity is maintained.

FIRE WALL. A fire-resistance-rated wall having protected openings, which restricts the spread of fire and extends continuously from the foundation to or through the roof, with sufficient structural stability under fire conditions to allow collapse of construction on either side without collapse of the wall.

The portion in red is something that many people mistakenly overlook. A firewall is a substantial wall that is still standing long after the flames are extinguished. This is not a wall constructed out of wood framing and drywall. Instead, this is a wall typically made from either brick, concrete, or cinder block.

NATIONAL FIRE PROTECTION ASSOCIATION

Whenever we talk about fire protection situations, I always want to see what the NFPA (National Fire Protection Association) has to say on the issue. The NFPA codes are not universally adopted, but they always error on the side of the higher law. Why? Because the NFPA’s top priority is fire protection. The NFPA 221 document is titled “Standard for High Challenge Fire Walls, Fire Walls, and Fire Barrier Walls”. It contains only 4 pages of information.

NFPA 2213.3.4.4 Fire Barrier Wall.A wall, other than a fire wall, having a fire resistance rating.3.3.4.5* Fire Wall.A wall separating buildings or subdividing a building to prevent the spread of fire and having a fire resistance rating and structural stability.3.3.4.6 High Challenge Fire Wall.A wall used to separate buildings or subdivide a building with high fire challenge occupancies, having enhanced fire resistance ratings and enhanced appurtenance protection to prevent the spread of fire, and having structural stability.

So the closest reference in the NFPA 211 to what we normally see in residential garages is a “Fire Barrier Wall”. Yes, “Fire Barrier Wall” is technically correct by the NFPA, but this term is NOT used in the IRC so I would be cautious with its use so as NOT TO CONFUSE in building areas where the NFPA codes are not adopted.

I next went to Wikipedia with the understanding of the information above and all of the text and images made sense.

WIKIPEDIA

From Wikipedia...

A firewall is a fireproof barrier used to prevent the spread of fire between or through buildings, structures, electrical substation transformers, or within an aircraft or vehicle.

Applications

Firewalls can be used to subdivide a building into separate fire areas and are located in accordance with the locally applicable building code. Firewalls are a portion of a building's passive fire protection systems...<SNIP>

Types

There are three main classifications of fire wall: firewalls, fire barrier walls, and high challenge firewalls. To the layperson, the common use of language typically includes all three when referring to a firewall unless distinguishing between them is necessary.

A firewall is a wall separating transformers, structures, or buildings or a wall subdividing a building to prevent the spread of fire and having a fire resistance rating and independent structural stability.

A fire barrier wall, also referred to as a fire partition, is a fire rated wall assembly which is not a fire wall. Typically, the main differences is that a fire barrier wall is not structurally self-sufficient, and does not extend through the roof, or necessarily to the underside of the floor above.

Fire barrier walls are continuous from an exterior wall to an exterior wall, or from a floor below to a floor or roof above, or from one fire barrier wall to another fire barrier wall, fire wall, or high challenge fire wall having a fire resistance rating of at least equal rating as required for the fire barrier wall. They are continuous through all concealed spaces (e.g., above a ceiling), but are not required to extend through concealed spaces if the construction assembly forming the bottom of the space has a fire resistance rating at least equal of the fire barrier wall.

A high challenge fire wall is a wall used to separate transformers, structures, or buildings or a wall subdividing a building with high fire challenge occupancies, having enhanced fire resistance ratings and enhanced appurtenance protection to prevent the spread of fire, and having structural stability.

Portions of structures that are subdivided by fire walls are permitted to be considered separate buildings, in that fire walls have sufficient structural stability to maintain the integrity of the wall in the event of the collapse of the building construction on either side of the wall.

Materials

Building and structural firewalls in North America are usually made of concrete, concrete blocks or reinforced concrete. Old walls, often built prior to World War II, will consist of brick.

IN CONCLUSION

So there you have it, the extended explanation to what was a very simple question by Ken Ives. So when you want to refer to “Firewalls” just think of Indigo Montoya (The Princess Bride) looking at you and saying, “I Do Not Think It Means What You Think It Means!”

It is my hope that:

1) We will drop the term Firewall from our residential reporting and conversations about wood framed gypsum board covered garage walls, when we are actually referring to fire separation walls, separation walls, or fire barrier walls.

2) We will continue to identify breeches in the garage fire separation walls.

3) We will identify piping that is inadequately sealed at their fire separation wall penetrations.

4) We will alter the text in our computer generated report templates to purge the use of the word firewall.

5) That we will refrain from using the word “intumescent” because nearly everybody will have to go to Dictionary.com to figure out what you are talking about.

WHAT ARE YOUR THOUGHTS ON FIREWALLS?

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About the author

Since 1995, Master Inspector Michael Leavitt has continued to run the finest inspection firm in Northern Utah. Michael Loves to write and this business portion of his blog captures fun moments and informative topics geared towards educating and entertaining homeowners and other real estate professionals. Michael has consistently built his inspection reputation by being extremely thorough in our inspection protocols. If you are looking for the finest inspection firm in Northern Utah, then confidently draw upon Michael’s experience and order your inspection today!!!